乌东德水库蓄水前后泥沙冲淤特性分析OA

Based on the measurements of cross-section in the Wudongde Reservoir between 2013 and 2023,this study analyzes the evolution of the characteristics of river channel erosion and sedimentation in different periods.The results indicate that during the natural period,influenced by sediment trapping effects of reser-voirs in the middle reaches of the Jinsha River and the Yalongjiang River,the main river channel is in slight e-rosion overall and can be spatially characterized by"upstream erosion and downstream sedimentation"During the construction phase,the spatial distribution pattern of"upstream erosion and downstream sedimentation"remains unchanged,but the river channel exhibits overall slight sedimentation.During the reservoir operation phase,a total of 55.836 million m3 of sediment has been deposited in the main and tributary channels,which resulting in a sedimentation loss of 0.95％of the dead storage capacity and an encroachment of 0.21％of the regulation storage capacity.The reservoir sedimentation can be characterized by"larger in the middle and smal-ler at both ends in longitudinal",and primarily deposition is in the dead storage capacity in vertical.Influenced by upstream sediment influx and backflow from the main stream,the Longchuan River estuary experiences the most significant sedimentation among tributary mouths,with the average deposition of 2.6 m in the estuary sec-tions.The Yalong River is in slight erosion with the average erosion of 0.1 m in the estuary sections.